Rendering devices are used to generate an image based on input image data. The input image data may be digital data contained in a file that is stored in a memory, such as a memory associated with a personal computer. Rendering devices may take many forms, and may be portable or essentially fixed. Examples of rendering devices include a cellular telephone, a facsimile machine, a computer with a display, and a printer. The cellular telephone may receive data from a wireless telephone network and may render text and graphical images on a display screen. The facsimile machine may render images and text onto paper or other suitable media. The computer may receive and store the image data and may concurrently, or subsequently, render the image on the display. Printers may receive image data from an attached computer, and may store the image data prior to rendering. Rendering devices used in connection with personal computers, or other computers and similar devices, are capable of rendering images and text either as bit map data or line drawing images. Image data supplied to the rendering device may be photograph data from a digital camera, data generated by a computer graphics package, or simply text data generated, for example, by a word processing program. Printers used to render the image data may be large format printers capable of printing posters, architectural images, and other large images. The printers may also include more common laser printers and ink jet printers.
In the specific case of a printer, print data received by the printer from a computer may include bit map data specifying an image in the form of a bit map, vector data specifying features in terms of vectors, and text data specifying text characters. For example, an architect's printing requirements may include a background photograph showing a building site, and superimposed, a computer generated image of a building having rendered texture and tones. The architect's image may also contain arrows and text pointing to individual features on the building, with the arrows and text superimposed either over the computer generated image or the background photograph.
However, many rendering devices do not have enough memory capacity to store an entire image to be rendered. As a result, the image to be rendered may be rendered with data missing, such a broad white stripe running the length of the image, for example.